Mechanical sweeper



FIG. 1 is a front perspective view of a mechanical sweeper which embodies my design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right side view thereof, the left side view thereof being a mirror image of the left side view thereof; and,

FIG. 5 is a top view thereof.

The portions of the mechanical sweeper in dotted lines form no part of our design. 

The ornamental design for a mechanical sweeper, as shown and described. 